Flat parts machined on all sides?


This is actually a practical application, as someone said he may want
me to do a parts run for him.
Let's say that out of a flat stock, I want to cut out a part and it
needs to be beveled on all sides.
I obviously cannot do it in one "start and forget" application, as at
some point the part would need to be clamped from top or something, to
avoid burs or unmachined edges.
Someone must have already invented a good scheme for doing so, any
ideas?
i
Reply to
Ignoramus28874
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Maybe have a look here
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at some of the T slot products . Can't give a direct URL as the site doesn't do that annoyingly. Maybe the Advant-edge clamp system.
Reply to
David Billington
You would use the components from your holdown kit, T nuts, studs, clamp bars, step blocks and flange nuts to clamp the part to the mill table. You would write your code to perform the cuts that clear the clamps and then stop. Then you install more clamps in the locations already milled, and once those are secure, you remove the original clamps and then start the remainder of the cycle to finish the machining.
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Reply to
Pete C.
Now that I thought some more about it, it is not as difficult. All I need it to stop the program, and use a Vise-Grip to clamp the part down to the backing, and then continue to cut it off.
i
Reply to
Ignoramus28874
Or this one if you're ok with an unknown import set cheaper than dirt ($29 web price):
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I got my set from MSC some time ago on sale for $69 or so which ended up being a TeCo set and is very nice.
Reply to
Pete C.
Vice-Grips are not intended as machining clamps. Try the clamp bars in the holdown kit, they are intended for the use and will give you high clamping pressures when used properly.
Reply to
Pete C.
BTW, have you been reading the Machining Fundamentals book? It explains various work holding scenarios including the clamp bars.
Reply to
Pete C.
Magnetic chuck ?
Reply to
fleetwood
Really hard to offer specific advice from a vague part description. But if the part has two parallel sides and is not too thin with respect to it's XY dimensions, consider using thicker material and machining 5 sides. Flip over, clamping on the now machined sides, and face to thickness. I've always tried to use the absolute minimum amount of material possible, but some one-off parts I'm doing right now, I decided to use this approach as to do otherwise would require multiple setups.
If you factor the additional cost for thicker material vs the extra labor for stopping, moving or adding/removing clamps, it can be quite a savings. If I hadn't already faced all the parts to thickness, I'd take a picture to show this clearly. It is btw, how a lot of production machining is done. Hmm, but I did still have the last profile in CAD, I just did a solids extrusion and output a GIF file. I'll email it direct.
Jon
Reply to
Jon Anderson
Hmm, but I don't seem to have your email. Ping me off list, my email is valid.
Jon
Reply to
Jon Anderson
I have been reading it, but not about clamps.
i
Reply to
Ignoramus28874
Good quality double stick tape is often used for thin work.
Use a heat gun to get it to release.
"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9
Reply to
Gunner Asch
The majority of parts you make will have workholding issues. This is probably the number one thing that separates a good CAM programmer from a terrible one. You have to know how to make a part before you automate it.
I'm big on optional stop in my program for clamp moves. Often a clamp can be moved while the machine runs. If you got it moved before it gets there, flip optional stop off and machine keeps going. if you didn't finish, machine stops and waits for you.
Karl
Reply to
Karl Townsend
Here is an easily made side clamp (scroll down to "T - Slot Fixture Clamps"):
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Bob
Reply to
Bob Engelhardt
Iggy,
It really seems your zeal for CNC has surpassed your level of manual craftsmanship. Why not slow down a bit and stop trying to digitize your entire life??
Bob Swinney
Now that I thought some more about it, it is not as difficult. All I need it to stop the program, and use a Vise-Grip to clamp the part down to the backing, and then continue to cut it off.
i
Reply to
Robert Swinney
I programmed this so that it is easy to reclamp this part. I will see how it goes.
i
Reply to
Ignoramus28874
Does anyone make NC clamps to automate that operation?
I really wish I were being flippant here, but I have this horrible suspicion that it's been done, and commercialized.
Reply to
Tim Wescott
craftsmanship. Why not slow
What..and have him not learn what the sound of CRUNCH! SPOING!BANGRATTLE is? Thats the sound of tooling shattering and bounching off the walls.
"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9
Reply to
Gunner Asch
craftsmanship. Why not slow
"Bounching?"
I think one would still get that opportunity even if one already knew manual machining techniques when one started in on CNC.
Reply to
Tim Wescott
Air clamps operated by the control and an M code, along with magnetic chucks and form chucks are all commonly used in manufacturing.
Gunner
"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9
Reply to
Gunner Asch

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